Rebreeching a barrel

[RR_Raptor65]

I'm looking to build another long gun pretty soon decided to choose between building a 1728 French musket, a Wender rifle or a Japanese Matchlock.

I've wanted to build those guns for awhile now, being unsatisfied with the Indian 1728s and none too eager to pay more than a grand for a TRS kit right this moment, the Wender I've been saving for the winter so that leaves the Tanegashima and the challenge it presents for me, on top of being 'different' than most long guns I just love working with brass.

But Tanegashimas seem to all have a breech plug at least 2" long. A picture is worth a thousand words so here's two:

My plan is to get a Colerain barrel (This one in particular, I have not ordered the barrel yet) and throw away the breech, then find a bolt at least 2-3/8" long with the proper threads, reshape the head and cut a shoulder at the tip as with a normal breech then drill and tap the breech in the barrel to accommodate the extra length.

Additionally, these guns had a large false muzzle like this:

I intend to have a large bar of hot rolled steel turned to shape, then I'll grind it to match the existing muzzle of the barrel and silver solder it in place, probably with a brass band to hide the joint. The bore of the false muzzle will be smooth but oversized so as to allow the ball and pressure to pass freely.

Have I gone completely mad? Any suggestions or corrections are much appreciated, I've never had to install the breech in a barrel before so this will be the maiden voyage if I do decide to go ahead with it.

 

[hawkeye2]

"Have I gone completely mad?" Absolutely, but we wouldn't be interested in your posts if they were just run of the mill. :wink:

A very interesting challenge and an equally interesting approach specially the muzzle. Keep us informed.

 

[RR_Raptor65]

I plan on doing this as a build-a-long, probably start on it next month. If the gun works and I do a good job, hopefully it'll be of use to someone who wants to build one as well because they look like they'd be a lot of fun to shoot.

 

[M. De Land]

The enlarged muzzle may not work out so well with black powder use as fouling can mess with accuracy at times in counter bore configurations which is what this set up looks to produce.
This was discovered in counter bore crowning for black powder cartridge rifles if I remember correctly. Mike D.

 

[RR_Raptor65]

I had considered that it might affect the accuracy, whether or not that will be the case here I don't know though, the bore on the false muzzle will be rather extreme, probably going from just over .50 to clear the rifling and tapering to .58 or .62, it really is just a false muzzle and hopefully the ball will just pass through freely.

I have no idea why they did this, maybe it was a feature of the original Portuguese matchlocks but not all the Japanese guns had such an extreme muzzle, some just had a simple ring around the outside while others had an extension of several inches. Mine will sit at about average in terms of length and width.

 

[rich pierce]

It's extremely unlikely the originals were rifled. If you decide to place a bell at the muzzle it would be good to have some indexing pins extending into the barrel and the false muzzle. Another option is to turn the existing muzzle down to a shoulder, thread the stub on the outside, and screw on a false muzzle with a corresponding threaded portion onto the stub.